Coronary artery thrombus may be a cause of, or a culprit in, acute coronary syndromes such as acute myocardial infarction and unstable angina. The presence of thrombus in the coronary artery, accompanying a significant artherosclerotic plaque narrowing, complicates optimal revascularization by percutaneous techniques such as angioplasty or stenting.
Distal embolization of thrombus into the distal coronary artery macro and micro circulation, which may for example occur during balloon angioplasty or coronary stenting, results in reduced TIMI (Thrombolysis in Myocardial Infarction) flow. Reduced TIMI flow or flow grade has been demonstrated to reduce patient outcomes in such studies as the PAMI (Primary Angioplasty in Myocardial Infarction) stent trials and the CADILLAC (Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications) clinical trials.
Dealing with coronary thrombus in these situations has been the subject and focus of many pharmacologic and endovascular techniques. Endovascular techniques of thrombus removal by thrombectomy devices have been well studied and several existing devices have been tried, such as the Possis AngioJet® System, which theoretically allows a physician to infuse medication directly into a thrombus and/or remove the thrombus through power pulse aspiration. Unfortunately, clinical trials conducted with the AngioJet® System have failed to demonstrate an advantage over previous techniques for treating coronary thrombus, such as balloon angioplasty prior to implantation of a stent.
Other means of treating coronary thrombus include passive aspiration by end-hole aspiration thrombectomy catheters such as the Export aspiration catheter. The Export aspiration catheter consists of a 5 French monorail catheter connected to an evacuated 20 ml syringe used to remove thrombotic debris. While rather extensively used, the efficacy of this treatment is limited by thrombus plugging the end hole during the procedure. Other, newer passive aspiration catheters like the Diver CE (manufactured by V3, Inc.) include a few side holes along the catheter body near the end of the aspiration catheter; yet such catheters are apt to plug with only slightly more thrombus than necessary to plug the passive export catheter.